Provided by: offlineimap_6.5.4-2_all 
NAME
offlineimap - Powerful IMAP/Maildir synchronization and reader support
DESCRIPTION
OfflineImap operates on a REMOTE and a LOCAL repository and synchronizes emails between them, so that you
can read the same mailbox from multiple computers. The REMOTE repository is some IMAP server, while LOCAL
can be either a local Maildir or another IMAP server.
Missing folders will be automatically created on both sides if needed. No folders will be deleted at the
moment.
Configuring OfflineImap in basic mode is quite easy, however it provides an amazing amount of flexibility
for those with special needs. You can specify the number of connections to your IMAP server, use
arbitrary python functions (including regular expressions) to limit the number of folders being
synchronized. You can transpose folder names between repositories using any python function, to mangle
and modify folder names on the LOCAL repository. There are six different ways to hand the IMAP password
to OfflineImap from console input, specifying in the configuration file, .netrc support, specifying in a
separate file, to using arbitrary python functions that somehow return the password. Finally, you can use
IMAPs IDLE infrastructure to always keep a connection to your IMAP server open and immediately be
notified (and synchronized) when a new mail arrives (aka Push mail).
Most configuration is done via the configuration file. However, any setting can also be overridden by
command line options handed to OfflineIMAP.
OfflineImap is well suited to be frequently invoked by cron jobs, or can run in daemon mode to
periodically check your email (however, it will exit in some error situations).
The documentation is included in the git repository and can be created by issueing make dev-doc in the
doc folder (python-sphinx required), or it can be viewed online at http://docs.offlineimap.org.
CONFIGURATION
OfflineIMAP is regulated by a configuration file that is normally stored in ~/.offlineimaprc. OfflineIMAP ships with a file named offlineimap.conf that you should copy to that location and then edit. This file is vital to proper operation of the system; it sets everything you need to run OfflineIMAP. Full documentation for the configuration file is included within the sample file. OfflineIMAP also ships a file named offlineimap.conf.minimal that you can also try. It's useful if you want to get started with the most basic feature set, and you can read about other features later with offlineimap.conf. Check out the Use Cases section for some example configurations.
OPTIONS
The command line options are described by issueing offlineimap --help. Details on their use can be found
either in the sample offlineimap.conf file or in the user docs at http://docs.offlineimap.org.
USER INTERFACES
OfflineIMAP has various user interfaces that let you choose how the program communicates information to
you. The 'ui' option in the configuration file specifies the user interface. The -u command-line option
overrides the configuration file setting. The available values for the configuration file or
command-line are described in this section.
Blinkenlights
Blinkenlights is an interface designed to be sleek, fun to watch, and informative of the overall picture
of what OfflineIMAP is doing.
Blinkenlights contains a row of "LEDs" with command buttons and a log. The log shows more detail about
what is happening and is color-coded to match the color of the lights.
Each light in the Blinkenlights interface represents a thread of execution -- that is, a particular task
that OfflineIMAP is performing right now. The colors indicate what task the particular thread is
performing, and are as follows:
• Black: indicates that this light's thread has terminated; it will light up again later when new threads
start up. So, black indicates no activity.
• Red (Meaning 1): is the color of the main program's thread, which basically does nothing but monitor
the others. It might remind you of HAL 9000 in 2001.
• Gray: indicates that the thread is establishing a new connection to the IMAP server.
• Purple: is the color of an account synchronization thread that is monitoring the progress of the
folders in that account (not generating any I/O).
• Cyan: indicates that the thread is syncing a folder.
• Green: means that a folder's message list is being loaded.
• Blue: is the color of a message synchronization controller thread.
• Orange: indicates that an actual message is being copied. (We use fuchsia for fake messages.)
• Red (Meaning 2): indicates that a message is being deleted.
• Yellow / bright orange: indicates that message flags are being added.
• Pink / bright red: indicates that message flags are being removed.
• Red / Black Flashing: corresponds to the countdown timer that runs between synchronizations.
The name of this interfaces derives from a bit of computer history. Eric Raymond's Jargon File defines
blinkenlights, in part, as:
Front-panel diagnostic lights on a computer, esp. a dinosaur. Now that dinosaurs are rare, this term
usually refers to status lights on a modem, network hub, or the like.
This term derives from the last word of the famous blackletter-Gothic sign in mangled pseudo-German that
once graced about half the computer rooms in the English-speaking world. One version ran in its entirety
as follows:
ACHTUNG! ALLES LOOKENSPEEPERS!
Das computermachine ist nicht fuer gefingerpoken und mittengrabben.
Ist easy schnappen der springenwerk, blowenfusen und poppencorken
mit spitzensparken. Ist nicht fuer gewerken bei das dumpkopfen.
Das rubbernecken sichtseeren keepen das cotten-pickenen hans in das
pockets muss; relaxen und watchen das blinkenlichten.
TTYUI
TTYUI interface is for people running in terminals. It prints out basic status messages and is generally
friendly to use on a console or xterm.
Basic
Basic is designed for situations in which OfflineIMAP will be run non-attended and the status of its
execution will be logged. This user interface is not capable of reading a password from the keyboard;
account passwords must be specified using one of the configuration file options. For example, it will not
print periodic sleep announcements and tends to be a tad less verbose, in general.
Quiet
It will output nothing except errors and serious warnings. Like Basic, this user interface is not
capable of reading a password from the keyboard; account passwords must be specified using one of the
configuration file options.
MachineUI
MachineUI generates output in a machine-parsable format. It is designed for other programs that will
interface to OfflineIMAP.
SYNCHRONIZATION PERFORMANCE
By default, we use fairly conservative settings that are safe for syncing but that might not be the best
performing one. Once you got everything set up and running, you might want to look into speeding up your
synchronization. Here are a couple of hints and tips on how to achieve this.
1. Use maxconnections > 1. By default we only use one connection to an IMAP server. Using 2 or even 3
speeds things up considerably in most cases. This setting goes into the [Repository XXX] section.
2. Use folderfilters. The quickest sync is a sync that can ignore some folders. I sort my inbox into
monthly folders, and ignore every folder that is more than 2-3 months old, this lets me only
inspect a fraction of my Mails on every sync. If you haven't done this yet, do it :). See the
folderfilter section the example offlineimap.conf.
3. The default status cache is a plain text file that will write out the complete file for each single
new message (or even changed flag) to a temporary file. If you have plenty of files in a folder,
this is a few hundred kilo to megabytes for each mail and is bound to make things slower. I
recommend to use the sqlite backend for that. See the status_backend = sqlite setting in the
example offlineimap.conf. You will need to have python-sqlite installed in order to use this. This
will save you plenty of disk activity. Do note that the sqlite backend is still considered
experimental as it has only been included recently (although a loss of your status cache should not
be a tragedy as that file can be rebuild automatically)
4. Use quick sync. A regular sync will request all flags and all UIDs of all mails in each folder
which takes quite some time. A 'quick' sync only compares the number of messages in a folder on the
IMAP side (it will detect flag changes on the Maildir side of things though). A quick sync on my
smallish account will take 7 seconds rather than 40 seconds. Eg, I run a cron script that does a
regular sync once a day, and does quick syncs (-q) only synchronizing the "-f INBOX" in between.
5. Turn off fsync. In the [general] section you can set fsync to True or False. If you want to play
110% safe and wait for all operations to hit the disk before continuing, you can set this to True.
If you set it to False, you lose some of that safety, trading it for speed.
UPGRADING FROM PLAIN TEXT CACHE TO SQLITE BASED CACHE
OfflineImap uses a cache to store the last know status of mails (flags etc). Historically that has meant
plain text files, but recently we introduced sqlite-based cache, which helps with performance and CPU
usage on large folders. Here is how to upgrade existing plain text cache installations to sqlite based
one:
1. Sync to make sure things are reasonably similar
2. Change the account section to status_backend = sqlite
3. A new sync will convert your plain text cache to an sqlite cache (but leave the old plain text cache
around for easy reverting) This should be quick and not involve any mail up/downloading.
4. See if it works :-)
5. If it does not work, go back to the old version or set status_backend=plain
6. Or, once you are sure it works, you can delete the .offlineimap/Account-foo/LocalStatus folder (the
new cache will be in the LocalStatus-sqlite folder)
SECURITY AND SSL
Some words on OfflineImap and its use of SSL/TLS. By default, we will connect using any method that
openssl supports, that is SSLv2, SSLv3, or TLSv1. Do note that SSLv2 is notoriously insecure and
deprecated. Unfortunately, python2 does not offer easy ways to disable SSLv2. It is recommended you test
your setup and make sure that the mail server does not use an SSLv2 connection. Use e.g. "openssl
s_client -host mail.server -port 443" to find out the connection that is used by default.
Certificate checking
Unfortunately, by default we will not verify the certificate of an IMAP TLS/SSL server we connect to, so
connecting by SSL is no guarantee against man-in-the-middle attacks. While verifying a server certificate
fingerprint is being planned, it is not implemented yet. There is currently only one safe way to ensure
that you connect to the correct server in an encrypted manner: You can specify a 'sslcacertfile' setting
in your repository section of offlineimap.conf pointing to a file that contains (among others) a CA
Certificate in PEM format which validating your server certificate. In this case, we will check that: 1)
The server SSL certificate is validated by the CA Certificate 2) The server host name matches the SSL
certificate 3) The server certificate is not past its expiration date. The FAQ contains an entry on how
to create your own certificate and CA certificate.
StartTLS
If you have not configured your account to connect via SSL anyway, OfflineImap will still attempt to set
up an SSL connection via the STARTTLS function, in case the imap server supports it. Do note, that there
is no certificate or fingerprint checking involved at all, when using STARTTLS (the underlying imaplib
library does not support this yet). This means that you will be protected against passively listening
eavesdroppers and they will not be able to see your password or email contents. However, this will not
protect you from active attacks, such as Man-In-The-Middle attacks which cause you to connect to the
wrong server and pretend to be your mail server. DO NOT RELY ON STARTTLS AS A SAFE CONNECTION
GUARANTEEING THE AUTHENTICITY OF YOUR IMAP SERVER!
UNIX SIGNALS
OfflineImap listens to the unix signals SIGUSR1, SIGUSR2, SIGTERM, SIGINT, SIGHUP:
If sent a SIGUSR1 it will abort any current (or next future) sleep of all accounts that are configured to
"autorefresh". In effect, this will trigger a full sync of all accounts to be performed as soon as
possible.
If sent a SIGUSR2, it will stop "autorefresh mode" for all accounts. That is, accounts will abort any
current sleep and will exit after a currently running synchronization has finished. This signal can be
used to gracefully exit out of a running offlineimap "daemon".
SIGTERM, SIGINT, SIGHUP are all treated to gracefully terminate as soon as possible. This means it will
finish syncing the current folder in each account, close keep alive connections, remove locks on the
accounts and exit. It may take up to 10 seconds, if autorefresh option is used.
FOLDER FILTERING AND NAMETRANS
OfflineImap offers flexible (and complex) ways of filtering and transforming folder names. Please see the
docs/dev-docs-src/folderfilters.rst document about details how to use folder filters and name
transformations. The documentation will be autogenerated by a "make dev-doc" in the docs directory. It is
also viewable at
:ref:`folder_filtering_and_name_translation`
System Message: ERROR/3 (MANUAL.rst:, line 347)
Unknown interpreted text role "ref".
KNOWN BUGS
SSL3 write pending
Users enabling SSL may hit a bug about "SSL3 write pending". If so, the account(s) will stay
unsynchronised from the time the bug appeared. Running OfflineIMAP again can help. We are still working
on this bug. Patches or detailed bug reports would be appreciated. Please check you're running the last
stable version and send us a report to the mailing list including the full log.
IDLE support
IDLE support is incomplete and experimental. Bugs may be encountered.
• No hook exists for "run after an IDLE response". Email will show up, but may not be processed until
the next refresh cycle.
• nametrans may not be supported correctly.
• IMAP IDLE <-> IMAP IDLE doesn't work yet.
• IDLE may only work "once" per refresh. If you encounter this bug, please send a report to the list!
Maildir support on Windows drive
Maildir uses colon caracter (:) in message file names. Colon is however forbidden character in windows
drives. There are several workarounds for that situation:
• Use "maildir-windows-compatible = yes" account OfflineIMAP configuration.
That makes OfflineIMAP to use exclamation mark (!) instead of colon for storing messages. Such files
can be written to windows partitions. But you will probably loose compatibility with other programs
trying to read the same Maildir.
Exclamation mark was chosen because of the note in http://docs.python.org/library/mailbox.html
If you have some messages already stored without this option, you will have to re-sync them again.
• Enable file name character translation in windows registry (not tested)
http://support.microsoft.com/kb/289627
• Use cygwin managed mount (not tested) not available anymore since cygwin 1.7
PITFALLS & ISSUES
Sharing a maildir with multiple IMAP servers
Generally a word of caution mixing IMAP repositories on the same Maildir root. You have to be careful
that you never use the same maildir folder for 2 IMAP servers. In the best case, the folder MD5 will
be different, and you will get a loop where it will upload your mails to both servers in turn
(infinitely!) as it thinks you have placed new mails in the local Maildir. In the worst case, the MD5
is the same (likely) and mail UIDs overlap (likely too!) and it will fail to sync some mails as it
thinks they are already existent.
I would create a new local Maildir Repository for the Personal Gmail and use a different root to be on
the safe side here. You could e.g. use ~/mail/Pro as Maildir root for the ProGmail and ~/mail/Personal
as root for the personal one.
If you then point your local mutt, or whatever MUA you use to ~/mail/ as root, it should still
recognize all folders. (see the 2 IMAP setup in the Use Cases section.
USE CASES
Sync from GMail to another IMAP server
This is an example of a setup where "TheOtherImap" requires all folders to be under INBOX:
[Repository Gmailserver-foo]
#This is the remote repository
type = Gmail
remotepass = XXX
remoteuser = XXX
# The below will put all GMAIL folders as sub-folders of the 'local' INBOX,
# assuming that your path separator on 'local' is a dot.
nametrans = lambda x: 'INBOX.' + x
[Repository TheOtherImap]
#This is the 'local' repository
type = IMAP
remotehost = XXX
remotepass = XXX
remoteuser = XXX
#Do not use nametrans here.
Selecting only a few folders to sync
Add this to the remote gmail repository section to only sync mails which are in a certain folder:
folderfilter = lambda folder: folder.startswith('MyLabel')
To only get the All Mail folder from a Gmail account, you would e.g. do:
folderfilter = lambda folder: folder.startswith('[Gmail]/All Mail')
Another nametrans transpose example
Put everything in a GMX. subfolder except for the boxes INBOX, Draft, and Sent which should keep the same
name:
nametrans: lambda folder: folder if folder in ['INBOX', 'Drafts', 'Sent'] \
else re.sub(r'^', r'GMX.', folder)
2 IMAP using name translations
Synchronizing 2 IMAP accounts to local Maildirs that are "next to each other", so that mutt can work on
both. Full email setup described by Thomas Kahle at http://dev.gentoo.org/~tomka/mail.html
offlineimap.conf:
[general]
accounts = acc1, acc2
maxsyncaccounts = 2
ui = ttyui
pythonfile=~/bin/offlineimap-helpers.py
socktimeout = 90
[Account acc1]
localrepository = acc1local
remoterepository = acc1remote
autorefresh = 2
[Account acc2]
localrepository = acc2local
remoterepository = acc2remote
autorefresh = 4
[Repository acc1local]
type = Maildir
localfolders = ~/Mail/acc1
[Repository acc2local]
type = Maildir
localfolders = ~/Mail/acc2
[Repository acc1remote]
type = IMAP
remotehost = imap.acc1.com
remoteusereval = get_username("imap.acc1.net")
remotepasseval = get_password("imap.acc1.net")
nametrans = oimaptransfolder_acc1
ssl = yes
maxconnections = 2
# Folders to get:
folderfilter = lambda foldername: foldername in [
'INBOX', 'Drafts', 'Sent', 'archiv']
[Repository acc2remote]
type = IMAP
remotehost = imap.acc2.net
remoteusereval = get_username("imap.acc2.net")
remotepasseval = get_password("imap.acc2.net")
nametrans = oimaptransfolder_acc2
ssl = yes
maxconnections = 2
One of the coolest things about offlineimap is that you can call arbitrary python code from your
configuration. To do this, specify a pythonfile with:
pythonfile=~/bin/offlineimap-helpers.py
Your pythonfile needs to contain implementations for the functions that you want to use in
offflineimaprc. The example uses it for two purposes: Fetching passwords from the gnome-keyring and
translating folder names on the server to local foldernames. An example implementation of get_username
and get_password showing how to query gnome-keyring is contained in
http://dev.gentoo.org/~tomka/mail-setup.tar.bz2 The folderfilter is a lambda term that, well, filters
which folders to get. The function oimaptransfolder_acc2 translates remote folders into local folders
with a very simple logic. The INBOX folder will have the same name as the account while any other folder
will have the account name and a dot as a prefix. This is useful for hierarchichal display in mutt.
Offlineimap handles the renaming correctly in both directions:
import re
def oimaptransfolder_acc1(foldername):
if(foldername == "INBOX"):
retval = "acc1"
else:
retval = "acc1." + foldername
retval = re.sub("/", ".", retval)
return retval
def oimaptransfolder_acc2(foldername):
if(foldername == "INBOX"):
retval = "acc2"
else:
retval = "acc2." + foldername
retval = re.sub("/", ".", retval)
return retval
AUTHOR
John Goerzen <jgoerzen@complete.org> & contributors
COPYRIGHT
This program is free software; you can redistribute it and/or modify it under the terms of the GNU
General Public License as published by the Free Software Foundation; either version 2 of the License, or
(at your option) any later version. This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU General Public License for more details.
2012-02-23 OFFLINEIMAP(1)